In 1953, at age 13, I was influenced by Abbé Chaisnot in Granville. When I was 17, I got my radio amateur’s licence (DR9KF). My decision to study medicine was ethically motivated, as a substitute for becoming a monk, and rewarded by my discovering Bertalanffy and later Teilhard de Chardin. Erich Letterer, my Ph’D adviser in pathology, with whom I had rediscovered immunological tolerance, had little patience with my experimental skill (the thesis had only 24 pages).

An idea I had had at age 22 on chemical evolution opened doors
when I mentioned it in letters to Carl Friedrich von Weizsächer and Konrad Lorenz
who became my second mentor. Deductive biology (a predictive approach to behavior and the brain) formed the topics of discussions. From Otto Köhler, whom I never met, I learned about the infant’s smile (I made a type copy of his paper). Bathing a baby once had been part of the pediatric curriculum. The next great influence was and is Reimara Waible who underserved by
made me her husband. She opened the door to America’s Center for Theoretical Biology. Bob Rosen gave me the manuscript of his Dynamical System Theory in Biology (Wiley, 1970) in 1969, an eye-opener and still very useful in its Poincaréan and Thomian spirit. So I became a member of the Rashevsky school, because Rosen loved his mentor so much. I met Bertalanffy (who invited us for Christmas) in Buffalo. R. W. Kaplan and U. Franck enabled my coming to Germany by getting stipends for Tübingen where I could habilitate in 1973 in Theoretical Biochemistry which suddenly gave me an identity and three years later a tenured docendship. The Center in Buffalo, unfortunately, dismantled because it allegedly had ``no tangible results’’.

Wolfgang Engelmann in Tübingen brought me in contact with Art Winfree who helped spawn the liquid digital computers. Michael and Debbie Conrad who
were at Tübingen at the time helped publish this work. Fritz Horn in Rochester also became a friend and Okan Gurel, White Plains, and Hans Degn and Lars-Folke Olsen in Odense and Dick Noyes, Oregon. I remember meeting Britten Chance and Benno Hess, Evgeny Sel’kov and Anatoly Zhabotinsky. Okan and Desnet, his chemist wife, brought us to Kyoto in 1975 where we met Anatol Rapoport and Masaya Yamaguti, who had graduated from a Zen master rather than a state school to become the weightless personality to anyone he interacted with - a holy man in mathematics. In the same year, Reimara and I were received and ravishly served as friends by Gregory Bateson in Santa Cruz to discuss the
theory of the simle. Bateson was ``not jealous’’ of his friend Konrad’s Nobel.

In the early 1970’s the first contacts with Steve Smale,Ilya Prigogine
and Ralph Abraham were fostered. The year 1975 also brought Art Winfree’s unheard-of
present about ten unpublished and published papers he had collected over the years on chaos - to encourage me in my search for a knotted oscillation. Later I learned that Stanislaw Ulam (whom I briefly met in 1983) had had a similar idea. Art was one of those giving person whom you can never pay back in a lifetime. My school friend Roland Wais and later my friend Peter Weibel,
pupil of Gödel’s, and Mohamed El Nashie, René Thomas and George Lasker are in the same category of being permanent givers. So in Jack Hudson, the colleague
who had the most good influences on our lives. The chaotic attractors of 1975 onwards owe their existence to Art Winfree’s having shared with me his obsession (as in Spielberg’s movie Close encounter of the third kind) with a three-dimensional puzzle.

Bob Rosen had this bend, too and now in France I met the third victim. For being strange - they cannot help visualizing things. 1976 was a year full of rewards with meeting Ed Lorenz, Steve Smale again, Richard FitzHugh, John Rinzel, John Ross, Rutherford Aris, Peter Richter, Bruce Clark, Yoshiki Kuramoto, Martin Gutzwiller. In 1977, Paul Rapp donated me the word hyperchaos
and the Directory of Tunes by Dennis Parsons. Christophe Zeeman came, the first genuine topologist I met before René Thom and Bob Gilmore. Frank Hoppensteadt visited, Hans Othmer, John Tyson, Len Pismen, Gottfried Mayer-Kress, Igor Gumowski, Gyorgyi Targonski, Agnes Babloyantz. In the same year I met David Ruelle, Edward Kerner and Christian Mira.

Okan’s 1977 conference of the New York Academy of Sciences, to which he invited me as a co-organizer was an incredible gift. Eberhard Hopf came, Benoît Mandelbrot of fracal fame, Bob May, the magicean, whom I secretely hold responsible for the chaos success, Jim Yorke, Bob Williams. The ``sound
of chaos’’ and ``screw chaos’’ were greated with joy. It was Jimmy Carter time: everyone was wearing a pullover (sweater). Theo Parlidis and Peter Decker were also there. So was Rolf Landauer who invited us to his home.

The year 1978 brought with Hoppensteadt’s conference Jack Hale and snap-back repellor Franck Marotto and... who visited me later in Tübingen. Ei Teramoto’s conference in Kyoto in the same year brought the friendship with Kazuhisha Tomita and Ichivo Tsuda and Kuni Kaneko. Collin Sparrow’s visit also fell in 1978. Crispin Gardiner and Raimund Kapral also visited.

Otto in the front of his analog computer (1979)

In 1979, I caught the hyperchaos fever in the (presumably false) assumption that the ``worst’’ or most beautiful complexity in four dimesions had been found. Gerald Baier and Sven Sable since extended it to arbitrarily high dimension - with still a single nonlinear term sufficing. It is probably a good idea if I slop here since the harnessing of chaos (the title of a Toyota
Conference 14 years later) was the main topic up to this point. This almost finishes my life in chaos.

O. E. Rössler, Chaotic behavior in simple reaction system, Zeitschrift für Naturfoschung A, 31, 259-264, 1976.
Abstract: Deterministic nonperiodic flow (of ``chaotic’’ or ``strange’’ or
``tumbling’’ type, respectively) was first observed, in a 3-component
differential system, by E. N. Lorenz in 1963. A 3-component abstract reaction
system showing the same qualitative behavior is indicated. It consists of
(i) an ordinary 2-variable chemical oscillator and (ii) an ordinary
single-variable chemical hysteresis system. According to the same dual
principle, many more analogous systems can be devised, no matter whether
chemical, biochemical, biophysical, ecological, sociological, economic, or
electronic in nature. Their dynamics are determined by the presence of a
``folded’’ Poincaré map. Under numerical simulation, the proposed chemical
system provides an almost ideal illustration to the underlying dynamical
prototype, the ``3-dimensional blender’’. Thus, continuous Euklidean dynamics
(and with it chemical kinetics) proves to be of equal interest in studying
chaos as discrete dynamical systems already have.

Z. Naturf. 31, 1664, 1976

O. E. Rössler, Different types of chaos in two simple differential equations, Zeitschrift für Naturforschung A, 31, 1664-1670, 1976.
Abstract: Different types of chaotic flow are possible in the 3-dimension state spaces of two simple nonlinear differential equations. The first equation consists of a 2-variable, double-focus subsystem complemented by a linearly coupled third variable. It produces at least three types of chaos: Lorenzian chaos, ``sandwich’’ chaos and ``horseshoe’’ chaos. Two figure 8-shaped chaotic regimes of the latter type are possible simultaneously, running through each other like 2 links of a chain. In the second equation, a transition between two different types of horseshoe chaos (spiral chaos and screw chaos) is possible. While sandwich chaos allows for a genuine strange attractor, the same has not yet been demonstrated for horseshoe chaos. Unlike the situation in the analogous chaos is a ``super-oscillation’’ (emergent with the third dimension), the existence of ``super-chaos’’ is postulated for the nect level.

A six-minute, super-8 sound film, demonstrating the different behavioral modes and their bifurcations in the 2 equations has been prepared. Chaos sounds as musical as a snore.